1
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Pretorius E, Kell DB. A Perspective on How Fibrinaloid Microclots and Platelet Pathology May be Applied in Clinical Investigations. Semin Thromb Hemost 2024; 50:537-551. [PMID: 37748515 PMCID: PMC11105946 DOI: 10.1055/s-0043-1774796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Microscopy imaging has enabled us to establish the presence of fibrin(ogen) amyloid (fibrinaloid) microclots in a range of chronic, inflammatory diseases. Microclots may also be induced by a variety of purified substances, often at very low concentrations. These molecules include bacterial inflammagens, serum amyloid A, and the S1 spike protein of severe acute respiratory syndrome coronavirus 2. Here, we explore which of the properties of these microclots might be used to contribute to differential clinical diagnoses and prognoses of the various diseases with which they may be associated. Such properties include distributions in their size and number before and after the addition of exogenous thrombin, their spectral properties, the diameter of the fibers of which they are made, their resistance to proteolysis by various proteases, their cross-seeding ability, and the concentration dependence of their ability to bind small molecules including fluorogenic amyloid stains. Measuring these microclot parameters, together with microscopy imaging itself, along with methodologies like proteomics and imaging flow cytometry, as well as more conventional assays such as those for cytokines, might open up the possibility of a much finer use of these microclot properties in generative methods for a future where personalized medicine will be standard procedures in all clotting pathology disease diagnoses.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Matieland, South Africa
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Douglas B. Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Matieland, South Africa
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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2
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Kell DB, Lip GYH, Pretorius E. Fibrinaloid Microclots and Atrial Fibrillation. Biomedicines 2024; 12:891. [PMID: 38672245 PMCID: PMC11048249 DOI: 10.3390/biomedicines12040891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 03/27/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Atrial fibrillation (AF) is a comorbidity of a variety of other chronic, inflammatory diseases for which fibrinaloid microclots are a known accompaniment (and in some cases, a cause, with a mechanistic basis). Clots are, of course, a well-known consequence of atrial fibrillation. We here ask the question whether the fibrinaloid microclots seen in plasma or serum may in fact also be a cause of (or contributor to) the development of AF. We consider known 'risk factors' for AF, and in particular, exogenous stimuli such as infection and air pollution by particulates, both of which are known to cause AF. The external accompaniments of both bacterial (lipopolysaccharide and lipoteichoic acids) and viral (SARS-CoV-2 spike protein) infections are known to stimulate fibrinaloid microclots when added in vitro, and fibrinaloid microclots, as with other amyloid proteins, can be cytotoxic, both by inducing hypoxia/reperfusion and by other means. Strokes and thromboembolisms are also common consequences of AF. Consequently, taking a systems approach, we review the considerable evidence in detail, which leads us to suggest that it is likely that microclots may well have an aetiological role in the development of AF. This has significant mechanistic and therapeutic implications.
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Affiliation(s)
- Douglas B. Kell
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Søltofts Plads, Building 220, 2800 Kongens Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
| | - Gregory Y. H. Lip
- Liverpool Centre for Cardiovascular Science at University of Liverpool, Liverpool John Moores University and Liverpool Heart and Chest Hospital, Liverpool L7 8TX, UK;
- Danish Center for Health Services Research, Department of Clinical Medicine, Aalborg University, 9220 Aalborg, Denmark
| | - Etheresia Pretorius
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
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3
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Bashir S, Aiman A, Chaudhary AA, Khan N, Ahanger IA, Sami N, Almugri EA, Ali MA, Khan SUD, Shahid M, Basir SF, Hassan MI, Islam A. Probing protein aggregation through spectroscopic insights and multimodal approaches: A comprehensive review for counteracting neurodegenerative disorders. Heliyon 2024; 10:e27949. [PMID: 38689955 PMCID: PMC11059433 DOI: 10.1016/j.heliyon.2024.e27949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/01/2024] [Accepted: 03/08/2024] [Indexed: 05/02/2024] Open
Abstract
Aberrant accumulation of protein misfolding can cause aggregation and fibrillation and is one of the primary characteristic features of neurodegenerative diseases. Because they are disordered, misfolded, and aggregated proteins pose a significant setback in drug designing. The structural study of intermediate steps in these kinds of aggregated proteins will allow us to determine the conformational changes as well as the probable pathways encompassing various neurodegenerative disorders. The analysis of protein aggregates involved in neurodegenerative diseases relies on a diverse toolkit of biophysical techniques, encompassing both morphological and non-morphological methods. Additionally, Thioflavin T (ThT) assays and Circular Dichroism (CD) spectroscopy facilitate investigations into aggregation kinetics and secondary structure alterations. The collective application of these biophysical techniques empowers researchers to comprehensively unravel the intricate nature of protein aggregates associated with neurodegeneration. Furthermore, the topics covered in this review have summed up a handful of well-established techniques used for the structural analysis of protein aggregation. This multifaceted approach advances our fundamental understanding of the underlying mechanisms driving neurodegenerative diseases and informs potential therapeutic strategies.
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Affiliation(s)
- Sania Bashir
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Ayesha Aiman
- Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Anis Ahmad Chaudhary
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia
| | - Nashrah Khan
- Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Ishfaq Ahmad Ahanger
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Neha Sami
- Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Eman Abdullah Almugri
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia
| | - Mohamed A.M. Ali
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia
- Department of Biochemistry, Faculty of Science, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Salah-Ud-Din Khan
- Department of Biochemistry, College of Medicine, Imam Mohammad Ibn Saud Islamic Universi-ty (IMSIU), Riyadh, 11623, Saudi Arabia
| | - Mohammad Shahid
- Department of Basic Medical Sciences, College of Medicine, Prince Sattam Bin Abdulaziz University, AlKharj, 11942, Saudi Arabia
| | - Seemi Farhat Basir
- Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
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4
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Kell DB, Khan MA, Kane B, Lip GYH, Pretorius E. Possible Role of Fibrinaloid Microclots in Postural Orthostatic Tachycardia Syndrome (POTS): Focus on Long COVID. J Pers Med 2024; 14:170. [PMID: 38392604 PMCID: PMC10890060 DOI: 10.3390/jpm14020170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/16/2024] [Accepted: 01/27/2024] [Indexed: 02/24/2024] Open
Abstract
Postural orthostatic tachycardia syndrome (POTS) is a common accompaniment of a variety of chronic, inflammatory diseases, including long COVID, as are small, insoluble, 'fibrinaloid' microclots. We here develop the argument, with accompanying evidence, that fibrinaloid microclots, through their ability to block the flow of blood through microcapillaries and thus cause tissue hypoxia, are not simply correlated with but in fact, by preceding it, may be a chief intermediary cause of POTS, in which tachycardia is simply the body's exaggerated 'physiological' response to hypoxia. Similar reasoning accounts for the symptoms bundled under the term 'fatigue'. Amyloids are known to be membrane disruptors, and when their targets are nerve membranes, this can explain neurotoxicity and hence the autonomic nervous system dysfunction that contributes to POTS. Taken together as a system view, we indicate that fibrinaloid microclots can serve to link POTS and fatigue in long COVID in a manner that is at once both mechanistic and explanatory. This has clear implications for the treatment of such diseases.
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Affiliation(s)
- Douglas B Kell
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- The Novo Nordisk Foundation Centre for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1, Matieland 7602, South Africa
| | - Muhammed Asad Khan
- Directorate of Respiratory Medicine, Manchester University Hospitals, Wythenshawe Hospital, Manchester M23 9LT, UK
| | - Binita Kane
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- Manchester University Foundation Trust and School of Biological Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Gregory Y H Lip
- Liverpool Centre for Cardiovascular Science at University of Liverpool, Liverpool John Moores University and Liverpool Heart & Chest Hospital, Liverpool L14 3PE, UK
- Danish Center for Health Services Research, Department of Clinical Medicine, Aalborg University, 9220 Aalborg, Denmark
| | - Etheresia Pretorius
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1, Matieland 7602, South Africa
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5
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Kreutzer AG, Parrocha CMT, Haerianardakani S, Guaglianone G, Nguyen JT, Diab MN, Yong W, Perez-Rosendahl M, Head E, Nowick JS. Antibodies Raised Against an Aβ Oligomer Mimic Recognize Pathological Features in Alzheimer's Disease and Associated Amyloid-Disease Brain Tissue. ACS CENTRAL SCIENCE 2024; 10:104-121. [PMID: 38292607 PMCID: PMC10823522 DOI: 10.1021/acscentsci.3c00592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 11/27/2023] [Accepted: 11/27/2023] [Indexed: 02/01/2024]
Abstract
Antibodies that target the β-amyloid peptide (Aβ) and its associated assemblies are important tools in Alzheimer's disease research and have emerged as promising Alzheimer's disease therapies. This paper reports the creation and characterization of a triangular Aβ trimer mimic composed of Aβ17-36 β-hairpins and the generation and study of polyclonal antibodies raised against the Aβ trimer mimic. The Aβ trimer mimic is covalently stabilized by three disulfide bonds at the corners of the triangular trimer to create a homogeneous oligomer. Structural, biophysical, and cell-based studies demonstrate that the Aβ trimer mimic shares characteristics with oligomers of full-length Aβ. X-ray crystallography elucidates the structure of the trimer and reveals that four copies of the trimer assemble to form a dodecamer. SDS-PAGE, size exclusion chromatography, and dynamic light scattering reveal that the trimer also forms higher-order assemblies in solution. Cell-based toxicity assays show that the trimer elicits LDH release, decreases ATP levels, and activates caspase-3/7 mediated apoptosis. Immunostaining studies on brain slices from people who lived with Alzheimer's disease and people who lived with Down syndrome reveal that the polyclonal antibodies raised against the Aβ trimer mimic recognize pathological features including different types of Aβ plaques and cerebral amyloid angiopathy.
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Affiliation(s)
- Adam G. Kreutzer
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Chelsea Marie T. Parrocha
- Department
of Pharmaceutical Sciences, University of
California Irvine, Irvine, California 92697, United States
| | - Sepehr Haerianardakani
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Gretchen Guaglianone
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Jennifer T. Nguyen
- Department
of Pharmaceutical Sciences, University of
California Irvine, Irvine, California 92697, United States
| | - Michelle N. Diab
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - William Yong
- Department
of Pathology and Laboratory Medicine, University
of California Irvine, Irvine, California 92697, United States
| | - Mari Perez-Rosendahl
- Department
of Pathology and Laboratory Medicine, University
of California Irvine, Irvine, California 92697, United States
| | - Elizabeth Head
- Department
of Pathology and Laboratory Medicine, University
of California Irvine, Irvine, California 92697, United States
| | - James S. Nowick
- Department
of Chemistry, University of California Irvine, Irvine, California 92697, United States
- Department
of Pharmaceutical Sciences, University of
California Irvine, Irvine, California 92697, United States
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6
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Cascella R, Banchelli M, Abolghasem Ghadami S, Ami D, Gagliani MC, Bigi A, Staderini T, Tampellini D, Cortese K, Cecchi C, Natalello A, Adibi H, Matteini P, Chiti F. An in situ and in vitro investigation of cytoplasmic TDP-43 inclusions reveals the absence of a clear amyloid signature. Ann Med 2023; 55:72-88. [PMID: 36495262 PMCID: PMC9746631 DOI: 10.1080/07853890.2022.2148734] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Introduction: Several neurodegenerative conditions are associated with a common histopathology within neurons of the central nervous system, consisting of the deposition of cytoplasmic inclusions of TAR DNA-binding protein 43 (TDP-43). Such inclusions have variably been described as morphologically and molecularly ordered aggregates having amyloid properties, as filaments without the cross-β-structure and dye binding specific for amyloid, or as amorphous aggregates with no defined structure and fibrillar morphology.Aims and Methods: Here we have expressed human full-length TDP-43 in neuroblastoma x spinal cord 34 (NSC-34) cells to investigate the morphological, structural, and tinctorial properties of TDP-43 inclusions in situ. We have used last-generation amyloid diagnostic probes able to cross the cell membrane and detect amyloid in the cytoplasm and have adopted Raman and Fourier transform infrared microspectroscopies to study in situ the secondary structure of the TDP-43 protein in the inclusions. We have then used transmission electron microscopy to study the morphology of the TDP-43 inclusions.Results: The results show the absence of amyloid dye binding, the lack of an enrichment of cross-β structure in the inclusions, and of a fibrillar texture in the round inclusions. The aggregates formed in vitro from the purified protein under conditions in which it is initially native also lack all these characteristics, ruling out a clear amyloid-like signature.Conclusions: These findings indicate a low propensity of TDP-43 to form amyloid fibrils and even non-amyloid filaments, under conditions in which the protein is initially native and undergoes its typical nucleus-to-cell mislocalization. It cannot be excluded that filaments emerge on the long time scale from such inclusions, but the high propensity of the protein to form initially other types of inclusions appear to be an essential characteristic of TDP-43 proteinopathies.KEY MESSAGESCytoplasmic inclusions of TDP-43 formed in NSC-34 cells do not stain with amyloid-diagnostic dyes, are not enriched with cross-β structure, and do not show a fibrillar morphology.TDP-43 assemblies formed in vitro from pure TDP-43 do not have any hallmarks of amyloid.
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Affiliation(s)
- Roberta Cascella
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Martina Banchelli
- Institute of Applied Physics "Nello Carrara", National Research Council, Sesto Fiorentino, Italy
| | | | - Diletta Ami
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy.,Milan Center of Neuroscience (NeuroMI), Milan, Italy
| | - Maria Cristina Gagliani
- Cellular Electron Microscopy Laboratory, Department of Experimental Medicine, University of Genova, Genoa, Italy
| | - Alessandra Bigi
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Tommaso Staderini
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Davide Tampellini
- U 1195 INSERM-Université Paris-Saclay, Paris, France.,Institut Professeur Baulieu, Paris, France
| | - Katia Cortese
- Cellular Electron Microscopy Laboratory, Department of Experimental Medicine, University of Genova, Genoa, Italy
| | - Cristina Cecchi
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Antonino Natalello
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy.,Milan Center of Neuroscience (NeuroMI), Milan, Italy
| | - Hadi Adibi
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Paolo Matteini
- Institute of Applied Physics "Nello Carrara", National Research Council, Sesto Fiorentino, Italy
| | - Fabrizio Chiti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
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7
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Ornithopoulou E, Åstrand C, Gustafsson L, Crouzier T, Hedhammar M. Self-Assembly of RGD-Functionalized Recombinant Spider Silk Protein into Microspheres in Physiological Buffer and in the Presence of Hyaluronic Acid. ACS APPLIED BIO MATERIALS 2023; 6:3696-3705. [PMID: 37579070 PMCID: PMC10521021 DOI: 10.1021/acsabm.3c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 08/07/2023] [Indexed: 08/16/2023]
Abstract
Biomaterials made of self-assembling protein building blocks are widely explored for biomedical applications, for example, as drug carriers, tissue engineering scaffolds, and functionalized coatings. It has previously been shown that a recombinant spider silk protein functionalized with a cell binding motif from fibronectin, FN-4RepCT (FN-silk), self-assembles into fibrillar structures at interfaces, i.e., membranes, fibers, or foams at liquid/air interfaces, and fibrillar coatings at liquid/solid interfaces. Recently, we observed that FN-silk also assembles into microspheres in the bulk of a physiological buffer (PBS) solution. Herein, we investigate the self-assembly process of FN-silk into microspheres in the bulk and how its progression is affected by the presence of hyaluronic acid (HA), both in solution and in a cross-linked HA hydrogel. Moreover, we characterize the size, morphology, mesostructure, and protein secondary structure of the FN-silk microspheres prepared in PBS and HA. Finally, we examine how the FN-silk microspheres can be used to mediate cell adhesion and spreading of human mesenchymal stem cells (hMSCs) during cell culture. These investigations contribute to our fundamental understanding of the self-assembly of silk protein into materials and demonstrate the use of silk microspheres as additives for cell culture applications.
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Affiliation(s)
- Eirini Ornithopoulou
- Department
of Protein Science, School of Chemistry, Biotechnology and Health
(CBH), KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - Carolina Åstrand
- Department
of Protein Science, School of Chemistry, Biotechnology and Health
(CBH), KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
- Spiber
Technologies AB, Roslagstullsbacken
15, 114 21 Stockholm, Sweden
| | - Linnea Gustafsson
- Spiber
Technologies AB, Roslagstullsbacken
15, 114 21 Stockholm, Sweden
- Division
of Micro and Nanosystems, School
of Electrical Engineering and Computer Science (EECS), KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - Thomas Crouzier
- Department
of Chemistry, School of Chemistry, Biotechnology and Health (CBH), KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - My Hedhammar
- Department
of Protein Science, School of Chemistry, Biotechnology and Health
(CBH), KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
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8
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Turner S, Laubscher GJ, Khan MA, Kell DB, Pretorius E. Accelerating discovery: A novel flow cytometric method for detecting fibrin(ogen) amyloid microclots using long COVID as a model. Heliyon 2023; 9:e19605. [PMID: 37809592 PMCID: PMC10558872 DOI: 10.1016/j.heliyon.2023.e19605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 10/10/2023] Open
Abstract
Long COVID has become a significant global health and economic burden, yet there are currently no established methods or diagnostic tools to identify which patients might benefit from specific treatments. One of the major pathophysiological factors contributing to Long COVID is the presence of hypercoagulability; this results in insoluble amyloid microclots that are resistant to fibrinolysis. Our previous research using fluorescence microscopy has demonstrated a significant amyloid microclot load in Long COVID patients. However, this approach lacked the elements of statistical robustness, objectivity, and rapid throughput. In the current study, we have used imaging flow cytometry for the first time to show a significantly increased concentration and size of these microclots. We identified notable variations in size and fluorescence between microclots in Long COVID and those of controls even using a 20× objective. By combining cell imaging and the high-event-rate and full-sample analysis nature of a conventional flow cytometer, imaging flow cytometry can eliminate erroneous results and increase accuracy in gating and analysis beyond what pure quantitative measurements from conventional flow cytometry can provide. Although imaging flow cytometry was used in our study, our results suggest that the signals indicating the presence of microclots should be easily detectable using a conventional flow cytometer. Flow cytometry is a more widely available technique than fluorescence microscopy and has been used in pathology laboratories for decades, rendering it a potentially more suitable and accessible method for detecting microclots in individuals suffering from Long COVID or conditions with similar pathology, such as myalgic encephalomyelitis.
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Affiliation(s)
- Simone Turner
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland, 7602, South Africa
| | | | - M Asad Khan
- Respiratory Medicine, Manchester University Hospitals, Wythenshawe Hospital, Manchester, M23 9LT, United Kingdom
| | - Douglas B. Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland, 7602, South Africa
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, L69 7ZB, UK
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kemitorvet 200, 2800, Kgs Lyngby, Denmark
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland, 7602, South Africa
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, L69 7ZB, UK
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9
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Kell DB, Pretorius E. Are fibrinaloid microclots a cause of autoimmunity in Long Covid and other post-infection diseases? Biochem J 2023; 480:1217-1240. [PMID: 37584410 DOI: 10.1042/bcj20230241] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/17/2023]
Abstract
It is now well established that the blood-clotting protein fibrinogen can polymerise into an anomalous form of fibrin that is amyloid in character; the resultant clots and microclots entrap many other molecules, stain with fluorogenic amyloid stains, are rather resistant to fibrinolysis, can block up microcapillaries, are implicated in a variety of diseases including Long COVID, and have been referred to as fibrinaloids. A necessary corollary of this anomalous polymerisation is the generation of novel epitopes in proteins that would normally be seen as 'self', and otherwise immunologically silent. The precise conformation of the resulting fibrinaloid clots (that, as with prions and classical amyloid proteins, can adopt multiple, stable conformations) must depend on the existing small molecules and metal ions that the fibrinogen may (and is some cases is known to) have bound before polymerisation. Any such novel epitopes, however, are likely to lead to the generation of autoantibodies. A convergent phenomenology, including distinct conformations and seeding of the anomalous form for initiation and propagation, is emerging to link knowledge in prions, prionoids, amyloids and now fibrinaloids. We here summarise the evidence for the above reasoning, which has substantial implications for our understanding of the genesis of autoimmunity (and the possible prevention thereof) based on the primary process of fibrinaloid formation.
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Affiliation(s)
- Douglas B Kell
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kemitorvet 200, 2800 Kgs Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
| | - Etheresia Pretorius
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
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10
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Nunes JM, Kell DB, Pretorius E. Cardiovascular and haematological pathology in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A role for viruses. Blood Rev 2023; 60:101075. [PMID: 36963989 PMCID: PMC10027292 DOI: 10.1016/j.blre.2023.101075] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 03/25/2023]
Abstract
ME/CFS is a debilitating chronic condition that often develops after viral or bacterial infection. Insight from the study of Long COVID/Post Acute Sequelae of COVID-19 (PASC), the post-viral syndrome associated with SARS-CoV-2 infection, might prove to be useful for understanding pathophysiological mechanisms of ME/CFS. Disease presentation is similar between the two conditions, and a subset of Long COVID patients meet the diagnostic criteria for ME/CFS. Since Long COVID is characterized by significant vascular pathology - including endothelial dysfunction, coagulopathy, and vascular dysregulation - the question of whether or not the same biological abnormalities are of significance in ME/CFS arises. Cardiac abnormalities have for a while now been documented in ME/CFS cohorts, with recent studies demonstrating major deficits in cerebral blood flow, and hence vascular dysregulation. A growing body of research is demonstrating that ME/CFS is accompanied by platelet hyperactivation, anomalous clotting, a procoagulant phenotype, and endothelial dysfunction. Endothelial damage and dysregulated clotting can impair substance exchange between blood and tissues, and result in hypoperfusion, which may contribute to the manifestation of certain ME/CFS symptoms. Here we review the ME/CFS literature to summarize cardiovascular and haematological findings documented in patients with the condition, and, in this context, briefly discuss the potential role of previously-implicated pathogens. Overall, cardiac and haematological abnormalities are present within ME/CFS cohorts. While atherosclerotic heart disease is not significantly associated with ME/CFS, suboptimal cardiovascular function defined by reduced cardiac output, impaired cerebral blood flow, and vascular dysregulation are, and these abnormalities do not appear to be influenced by deconditioning. Rather, these cardiac abnormalities may result from dysfunction in the (autonomic) nervous system. Plenty of recently published studies are demonstrating significant platelet hyperactivity and endothelial dysfunction in ME/CFS, as well as anomalous clotting processes. It is of particular importance to determine to what extent these cardiovascular and haematological abnormalities contribute to symptom severity, and if these two systems can be targeted for therapeutic purposes. Viral reservoirs of herpesviruses exist in ME/CFS, and most likely contribute to cardiovascular and haematological dysfunction directly or indirectly. This review highlights the potential of studying cardiac functioning, the vasculature, and coagulation system in ME/CFS.
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Affiliation(s)
- Jean M Nunes
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland 7602, South Africa; Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK; The Novo Nordisk Foundation Centre for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland 7602, South Africa; Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK.
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11
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Housmans JAJ, Wu G, Schymkowitz J, Rousseau F. A guide to studying protein aggregation. FEBS J 2023; 290:554-583. [PMID: 34862849 DOI: 10.1111/febs.16312] [Citation(s) in RCA: 50] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/18/2021] [Accepted: 12/03/2021] [Indexed: 02/04/2023]
Abstract
Disrupted protein folding or decreased protein stability can lead to the accumulation of (partially) un- or misfolded proteins, which ultimately cause the formation of protein aggregates. Much of the interest in protein aggregation is associated with its involvement in a wide range of human diseases and the challenges it poses for large-scale biopharmaceutical manufacturing and formulation of therapeutic proteins and peptides. On the other hand, protein aggregates can also be functional, as observed in nature, which triggered its use in the development of biomaterials or therapeutics as well as for the improvement of food characteristics. Thus, unmasking the various steps involved in protein aggregation is critical to obtain a better understanding of the underlying mechanism of amyloid formation. This knowledge will allow a more tailored development of diagnostic methods and treatments for amyloid-associated diseases, as well as applications in the fields of new (bio)materials, food technology and therapeutics. However, the complex and dynamic nature of the aggregation process makes the study of protein aggregation challenging. To provide guidance on how to analyse protein aggregation, in this review we summarize the most commonly investigated aspects of protein aggregation with some popular corresponding methods.
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Affiliation(s)
- Joëlle A J Housmans
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Guiqin Wu
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Frederic Rousseau
- Switch Laboratory, VIB Center for Brain and Disease Research, Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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12
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Gonçalves CA, Bobermin LD, Sesterheim P, Netto CA. SARS-CoV-2-Induced Amyloidgenesis: Not One, but Three Hypotheses for Cerebral COVID-19 Outcomes. Metabolites 2022; 12:1099. [PMID: 36422238 PMCID: PMC9692683 DOI: 10.3390/metabo12111099] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 09/29/2022] [Accepted: 11/09/2022] [Indexed: 01/17/2024] Open
Abstract
The main neuropathological feature of Alzheimer's disease (AD) is extracellular amyloid deposition in senile plaques, resulting from an imbalance between the production and clearance of amyloid beta peptides. Amyloid deposition is also found around cerebral blood vessels, termed cerebral amyloid angiopathy (CAA), in 90% of AD cases. Although the relationship between these two amyloid disorders is obvious, this does not make CAA a characteristic of AD, as 40% of the non-demented population presents this derangement. AD is predominantly sporadic; therefore, many factors contribute to its genesis. Herein, the starting point for discussion is the COVID-19 pandemic that we are experiencing and how SARS-CoV-2 may be able to, both directly and indirectly, contribute to CAA, with consequences for the outcome and extent of the disease. We highlight the role of astrocytes and endothelial cells in the process of amyloidgenesis, as well as the role of other amyloidgenic proteins, such as fibrinogen and serum amyloid A protein, in addition to the neuronal amyloid precursor protein. We discuss three independent hypotheses that complement each other to explain the cerebrovascular amyloidgenesis that may underlie long-term COVID-19 and new cases of dementia.
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Affiliation(s)
- Carlos-Alberto Gonçalves
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre 90035-003, Brazil
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre 90035-003, Brazil
| | - Larissa Daniele Bobermin
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre 90035-003, Brazil
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre 90035-003, Brazil
| | - Patricia Sesterheim
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre 90035-003, Brazil
- Centro Estadual de Vigilância Sanitária do Rio Grande do Sul (CEVS-RS), Porto Alegre 90450-190, Brazil
| | - Carlos Alexandre Netto
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre 90035-003, Brazil
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre 90035-003, Brazil
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13
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Grobbelaar LM, Kruger A, Venter C, Burger EM, Laubscher GJ, Maponga TG, Kotze MJ, Kwaan HC, Miller JB, Fulkerson D, Huff W, Chang E, Wiarda G, Bunch CM, Walsh MM, Raza S, Zamlut M, Moore HB, Moore EE, Neal MD, Kell DB, Pretorius E. Relative Hypercoagulopathy of the SARS-CoV-2 Beta and Delta Variants when Compared to the Less Severe Omicron Variants Is Related to TEG Parameters, the Extent of Fibrin Amyloid Microclots, and the Severity of Clinical Illness. Semin Thromb Hemost 2022; 48:858-868. [PMID: 36174604 DOI: 10.1055/s-0042-1756306] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Earlier variants of SARS-CoV-2 have been associated with plasma hypercoagulability (as judged by thromboelastography) and an extensive formation of fibrin amyloid microclots, which are considered to contribute to the pathology of the coronavirus 2019 disease (COVID-19). The newer Omicron variants appear to be far more transmissible, but less virulent, even when taking immunity acquired from previous infections or vaccination into account. We here show that while the clotting parameters associated with Omicron variants are significantly raised over those of healthy, matched controls, they are only raised to levels significantly lower than those seen with more severe variants such as beta and delta. We also observed that individuals infected with omicron variants manifested less extensive microclot formation in platelet-poor plasma compared with those harboring the more virulent variants. The measurement of clotting effects between the different variants acts as a kind of "internal control" that demonstrates the relationship between the extent of coagulopathies and the virulence of the variant of interest. This adds to the evidence that microclots may play an important role in reflecting the severity of symptoms observed in COVID-19.
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Affiliation(s)
- Lize M Grobbelaar
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Matieland, South Africa
| | - Arneaux Kruger
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Matieland, South Africa
| | - Chantelle Venter
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Matieland, South Africa
| | | | | | - Tongai G Maponga
- Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, Cape Town, South Africa
| | - Maritha J Kotze
- Division of Chemical Pathology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University and National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa
| | - Hau C Kwaan
- Division of Hematology and Oncology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Joseph B Miller
- Departments of Emergency Medicine and Internal Medicine, Henry Ford Hospital, Detroit, Michigan
| | - Daniel Fulkerson
- Department of Neurosurgery, St. Joseph Regional Medical Center, Mishawaka, Indiana
| | - Wei Huff
- Department of Neurosurgery, St. Joseph Regional Medical Center, Mishawaka, Indiana
| | - Eric Chang
- Indiana University School of Medicine - South Bend, Notre Dame, Indiana
| | - Grant Wiarda
- Department of Internal Medicine, Saint Joseph Regional Medical Center, Mishawaka, Indiana
| | - Connor M Bunch
- Departments of Emergency Medicine and Internal Medicine, Henry Ford Hospital, Detroit, Michigan
| | - Mark M Walsh
- Indiana University School of Medicine - South Bend, Notre Dame, Indiana.,Department of Internal Medicine, Saint Joseph Regional Medical Center, Mishawaka, Indiana.,Department of Emergency Medicine, Saint Joseph Regional Medical Center, Mishawaka, Indiana
| | - Syed Raza
- Department of Critical Care Medicine, Saint Joseph Regional Medical Center, Mishawaka, Indiana
| | - Mahmud Zamlut
- Department of Critical Care Medicine, Saint Joseph Regional Medical Center, Mishawaka, Indiana
| | - Hunter B Moore
- Division of Transplant Surgery, Department of Surgery, Denver Health and University of Colorado Health Sciences Center, Denver, Colorado
| | - Ernest E Moore
- Department of Surgery, Ernest E. Moore Shock Trauma Center at Denver Health and University of Colorado Health Sciences Center, Denver, Colorado
| | - Matthew D Neal
- Pittsburgh Trauma Research Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Matieland, South Africa.,Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, England, United Kingdom.,The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Matieland, South Africa.,The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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14
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The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications. Biochem J 2022; 479:1653-1708. [PMID: 36043493 PMCID: PMC9484810 DOI: 10.1042/bcj20220154] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/09/2022] [Accepted: 08/10/2022] [Indexed: 02/07/2023]
Abstract
Ischaemia–reperfusion (I–R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I–R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.
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15
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Kumar ST, Mahul-Mellier AL, Hegde RN, Rivière G, Moons R, Ibáñez de Opakua A, Magalhães P, Rostami I, Donzelli S, Sobott F, Zweckstetter M, Lashuel HA. A NAC domain mutation (E83Q) unlocks the pathogenicity of human alpha-synuclein and recapitulates its pathological diversity. SCIENCE ADVANCES 2022; 8:eabn0044. [PMID: 35486726 PMCID: PMC9054026 DOI: 10.1126/sciadv.abn0044] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The alpha-synuclein mutation E83Q, the first in the NAC domain of the protein, was recently identified in a patient with dementia with Lewy bodies. We investigated the effects of this mutation on the aggregation of aSyn monomers and the structure, morphology, dynamic, and seeding activity of the aSyn fibrils in neurons. We found that it markedly accelerates aSyn fibrillization and results in the formation of fibrils with distinct structural and dynamic properties. In cells, this mutation is associated with higher levels of aSyn, accumulation of pS129, and increased toxicity. In a neuronal seeding model of Lewy body (LB) formation, the E83Q mutation significantly enhances the internalization of fibrils into neurons, induces higher seeding activity, and results in the formation of diverse aSyn pathologies, including the formation of LB-like inclusions that recapitulate the immunohistochemical and morphological features of brainstem LBs observed in brains of patients with Parkinson's disease.
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Affiliation(s)
- Senthil T. Kumar
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anne-Laure Mahul-Mellier
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ramanath Narayana Hegde
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Gwladys Rivière
- Research Group Translational Structural Biology, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Von-Siebold-Str. 3a, 37075 Göttingen, Germany
| | - Rani Moons
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Alain Ibáñez de Opakua
- Research Group Translational Structural Biology, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Von-Siebold-Str. 3a, 37075 Göttingen, Germany
| | - Pedro Magalhães
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Iman Rostami
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sonia Donzelli
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Frank Sobott
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
- School of Molecular and Cellular Biology and The Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, UK
| | - Markus Zweckstetter
- Research Group Translational Structural Biology, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Von-Siebold-Str. 3a, 37075 Göttingen, Germany
- Department for NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Hilal A. Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Corresponding author.
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16
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Kell DB, Laubscher GJ, Pretorius E. A central role for amyloid fibrin microclots in long COVID/PASC: origins and therapeutic implications. Biochem J 2022; 479:537-559. [PMID: 35195253 PMCID: PMC8883497 DOI: 10.1042/bcj20220016] [Citation(s) in RCA: 103] [Impact Index Per Article: 51.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 12/15/2022]
Abstract
Post-acute sequelae of COVID (PASC), usually referred to as 'Long COVID' (a phenotype of COVID-19), is a relatively frequent consequence of SARS-CoV-2 infection, in which symptoms such as breathlessness, fatigue, 'brain fog', tissue damage, inflammation, and coagulopathies (dysfunctions of the blood coagulation system) persist long after the initial infection. It bears similarities to other post-viral syndromes, and to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Many regulatory health bodies still do not recognize this syndrome as a separate disease entity, and refer to it under the broad terminology of 'COVID', although its demographics are quite different from those of acute COVID-19. A few years ago, we discovered that fibrinogen in blood can clot into an anomalous 'amyloid' form of fibrin that (like other β-rich amyloids and prions) is relatively resistant to proteolysis (fibrinolysis). The result, as is strongly manifested in platelet-poor plasma (PPP) of individuals with Long COVID, is extensive fibrin amyloid microclots that can persist, can entrap other proteins, and that may lead to the production of various autoantibodies. These microclots are more-or-less easily measured in PPP with the stain thioflavin T and a simple fluorescence microscope. Although the symptoms of Long COVID are multifarious, we here argue that the ability of these fibrin amyloid microclots (fibrinaloids) to block up capillaries, and thus to limit the passage of red blood cells and hence O2 exchange, can actually underpin the majority of these symptoms. Consistent with this, in a preliminary report, it has been shown that suitable and closely monitored 'triple' anticoagulant therapy that leads to the removal of the microclots also removes the other symptoms. Fibrin amyloid microclots represent a novel and potentially important target for both the understanding and treatment of Long COVID and related disorders.
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Affiliation(s)
- Douglas B. Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kemitorvet 200, 2800 Kgs Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, South Africa
| | | | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, South Africa
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17
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Page MJ, Kell DB, Pretorius E. The Role of Lipopolysaccharide-Induced Cell Signalling in Chronic Inflammation. CHRONIC STRESS (THOUSAND OAKS, CALIF.) 2022; 6:24705470221076390. [PMID: 35155966 PMCID: PMC8829728 DOI: 10.1177/24705470221076390] [Citation(s) in RCA: 64] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 01/11/2022] [Indexed: 12/20/2022]
Abstract
Lipopolysaccharide (LPS) is the main structural component of the outer membrane of most Gram-negative bacteria and has diverse immunostimulatory and procoagulant effects. Even though LPS is well described for its role in the pathology of sepsis, considerable evidence demonstrates that LPS-induced signalling and immune dysregulation are also relevant in the pathophysiology of many diseases, characteristically where endotoxaemia is less severe. These diseases are typically chronic and progressive in nature and span broad classifications, including neurodegenerative, metabolic, and cardiovascular diseases. This Review reappraises the mechanisms of LPS-induced signalling and emphasises the crucial contribution of LPS to the pathology of multiple chronic diseases, beyond conventional sepsis. This perspective asserts that new ways of approaching chronic diseases by targeting LPS-driven pathways may be of therapeutic benefit in a wide range of chronic inflammatory conditions.
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Affiliation(s)
| | - Douglas B Kell
- Stellenbosch University, Stellenbosch, South Africa.,Institute of Integrative Biology, University of Liverpool, Liverpool, UK.,The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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18
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Kell DB. A protet-based, protonic charge transfer model of energy coupling in oxidative and photosynthetic phosphorylation. Adv Microb Physiol 2021; 78:1-177. [PMID: 34147184 DOI: 10.1016/bs.ampbs.2021.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Textbooks of biochemistry will explain that the otherwise endergonic reactions of ATP synthesis can be driven by the exergonic reactions of respiratory electron transport, and that these two half-reactions are catalyzed by protein complexes embedded in the same, closed membrane. These views are correct. The textbooks also state that, according to the chemiosmotic coupling hypothesis, a (or the) kinetically and thermodynamically competent intermediate linking the two half-reactions is the electrochemical difference of protons that is in equilibrium with that between the two bulk phases that the coupling membrane serves to separate. This gradient consists of a membrane potential term Δψ and a pH gradient term ΔpH, and is known colloquially as the protonmotive force or pmf. Artificial imposition of a pmf can drive phosphorylation, but only if the pmf exceeds some 150-170mV; to achieve in vivo rates the imposed pmf must reach 200mV. The key question then is 'does the pmf generated by electron transport exceed 200mV, or even 170mV?' The possibly surprising answer, from a great many kinds of experiment and sources of evidence, including direct measurements with microelectrodes, indicates it that it does not. Observable pH changes driven by electron transport are real, and they control various processes; however, compensating ion movements restrict the Δψ component to low values. A protet-based model, that I outline here, can account for all the necessary observations, including all of those inconsistent with chemiosmotic coupling, and provides for a variety of testable hypotheses by which it might be refined.
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Affiliation(s)
- Douglas B Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative, Biology, University of Liverpool, Liverpool, United Kingdom; The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
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19
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van Vuuren MJ, Nell TA, Carr JA, Kell DB, Pretorius E. Iron Dysregulation and Inflammagens Related to Oral and Gut Health Are Central to the Development of Parkinson's Disease. Biomolecules 2020; 11:E30. [PMID: 33383805 PMCID: PMC7823713 DOI: 10.3390/biom11010030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/16/2020] [Accepted: 12/24/2020] [Indexed: 12/12/2022] Open
Abstract
Neuronal lesions in Parkinson's disease (PD) are commonly associated with α-synuclein (α-Syn)-induced cell damage that are present both in the central and peripheral nervous systems of patients, with the enteric nervous system also being especially vulnerable. Here, we bring together evidence that the development and presence of PD depends on specific sets of interlinking factors that include neuroinflammation, systemic inflammation, α-Syn-induced cell damage, vascular dysfunction, iron dysregulation, and gut and periodontal dysbiosis. We argue that there is significant evidence that bacterial inflammagens fuel this systemic inflammation, and might be central to the development of PD. We also discuss the processes whereby bacterial inflammagens may be involved in causing nucleation of proteins, including of α-Syn. Lastly, we review evidence that iron chelation, pre-and probiotics, as well as antibiotics and faecal transplant treatment might be valuable treatments in PD. A most important consideration, however, is that these therapeutic options need to be validated and tested in randomized controlled clinical trials. However, targeting underlying mechanisms of PD, including gut dysbiosis and iron toxicity, have potentially opened up possibilities of a wide variety of novel treatments, which may relieve the characteristic motor and nonmotor deficits of PD, and may even slow the progression and/or accompanying gut-related conditions of the disease.
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Affiliation(s)
- Marthinus Janse van Vuuren
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (M.J.v.V.); (T.A.N.)
| | - Theodore Albertus Nell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (M.J.v.V.); (T.A.N.)
| | - Jonathan Ambrose Carr
- Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
| | - Douglas B. Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (M.J.v.V.); (T.A.N.)
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Chemitorvet 200, 2800 Kongens Lyngby, Denmark
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (M.J.v.V.); (T.A.N.)
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Pretorius E, Venter C, Laubscher GJ, Lourens PJ, Steenkamp J, Kell DB. Prevalence of readily detected amyloid blood clots in 'unclotted' Type 2 Diabetes Mellitus and COVID-19 plasma: a preliminary report. Cardiovasc Diabetol 2020; 19:193. [PMID: 33203441 PMCID: PMC7670290 DOI: 10.1186/s12933-020-01165-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 10/29/2020] [Indexed: 12/24/2022] Open
Abstract
Background Type 2 Diabetes Mellitus (T2DM) is a well-known comorbidity to COVID-19 and coagulopathies are a common accompaniment to both T2DM and COVID-19. In addition, patients with COVID-19 are known to develop micro-clots within the lungs. The rapid detection of COVID-19 uses genotypic testing for the presence of SARS-Cov-2 virus in nasopharyngeal swabs, but it can have a poor sensitivity. A rapid, host-based physiological test that indicated clotting severity and the extent of clotting pathologies in the individual who was infected or not would be highly desirable. Methods Platelet poor plasma (PPP) was collected and frozen. On the day of analysis, PPP samples were thawed and analysed. We show here that microclots can be detected in the native plasma of twenty COVID-19, as well as ten T2DM patients, without the addition of any clotting agent, and in particular that such clots are amyloid in nature as judged by a standard fluorogenic stain. Results were compared to ten healthy age-matched individuals. Results In COVID-19 plasma these microclots are significantly increased when compared to the levels in T2DM. Conclusions This fluorogenic test may provide a rapid and convenient test with 100% sensitivity (P < 0.0001) and is consistent with the recognition that the early detection and prevention of such clotting can have an important role in therapy.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland, 7602, South Africa.
| | - Chantelle Venter
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland, 7602, South Africa
| | - Gert Jacobus Laubscher
- Mediclinic Stellenbosch, Suite 104, 1 Elsie du Toit Street, Stellenbosch, 7600, South Africa
| | - Petrus Johannes Lourens
- Mediclinic Stellenbosch, Suite 104, 1 Elsie du Toit Street, Stellenbosch, 7600, South Africa
| | - Janami Steenkamp
- PathCare Laboratories, PathCare Business Centre, Neels Bothma Street, N1 City, 7460, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1, Matieland, 7602, South Africa. .,Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool, L69 7ZB, UK. .,The Novo Nordisk Foundation Centre for Biosustainability, Building 220, Kemitorvet, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
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21
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Venter C, Bezuidenhout JA, Laubscher GJ, Lourens PJ, Steenkamp J, Kell DB, Pretorius E. Erythrocyte, Platelet, Serum Ferritin, and P-Selectin Pathophysiology Implicated in Severe Hypercoagulation and Vascular Complications in COVID-19. Int J Mol Sci 2020; 21:E8234. [PMID: 33153161 PMCID: PMC7662625 DOI: 10.3390/ijms21218234] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/22/2020] [Accepted: 10/26/2020] [Indexed: 01/08/2023] Open
Abstract
Progressive respiratory failure is seen as a major cause of death in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2)-induced infection. Relatively little is known about the associated morphologic and molecular changes in the circulation of these patients. In particular, platelet and erythrocyte pathology might result in severe vascular issues, and the manifestations may include thrombotic complications. These thrombotic pathologies may be both extrapulmonary and intrapulmonary and may be central to respiratory failure. Previously, we reported the presence of amyloid microclots in the circulation of patients with coronavirus disease 2019 (COVID-19). Here, we investigate the presence of related circulating biomarkers, including C-reactive protein (CRP), serum ferritin, and P-selectin. These biomarkers are well-known to interact with, and cause pathology to, platelets and erythrocytes. We also study the structure of platelets and erythrocytes using fluorescence microscopy (using the markers PAC-1 and CD62PE) and scanning electron microscopy. Thromboelastography and viscometry were also used to study coagulation parameters and plasma viscosity. We conclude that structural pathologies found in platelets and erythrocytes, together with spontaneously formed amyloid microclots, may be central to vascular changes observed during COVID-19 progression, including thrombotic microangiopathy, diffuse intravascular coagulation, and large-vessel thrombosis, as well as ground-glass opacities in the lungs. Consequently, this clinical snapshot of COVID-19 strongly suggests that it is also a true vascular disease and considering it as such should form an essential part of a clinical treatment regime.
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Affiliation(s)
- Chantelle Venter
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (C.V.); (J.A.B.)
| | - Johannes Andries Bezuidenhout
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (C.V.); (J.A.B.)
| | - Gert Jacobus Laubscher
- Suite 104, 1 Elsie du Toit Street, Mediclinic Stellenbosch, Stellenbosch 7600, South Africa; (G.J.L.); (P.J.L.)
| | - Petrus Johannes Lourens
- Suite 104, 1 Elsie du Toit Street, Mediclinic Stellenbosch, Stellenbosch 7600, South Africa; (G.J.L.); (P.J.L.)
| | - Janami Steenkamp
- PathCare Laboratories, PathCare Business Centre, PathCare Park, Neels Bothma Street, N1 City 7460, South Africa;
| | - Douglas B. Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (C.V.); (J.A.B.)
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- The Novo Nordisk Foundation Centre for Biosustainability, Building 220, Kemitorvet, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa; (C.V.); (J.A.B.)
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22
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Nunes JM, Fillis T, Page MJ, Venter C, Lancry O, Kell DB, Windberger U, Pretorius E. Gingipain R1 and Lipopolysaccharide From Porphyromonas gingivalis Have Major Effects on Blood Clot Morphology and Mechanics. Front Immunol 2020; 11:1551. [PMID: 32793214 PMCID: PMC7393971 DOI: 10.3389/fimmu.2020.01551] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/12/2020] [Indexed: 12/19/2022] Open
Abstract
Background:Porphyromonas gingivalis and its inflammagens are associated with a number of systemic diseases, such as cardiovascular disease and type 2 diabetes (T2DM). The proteases, gingipains, have also recently been identified in the brains of Alzheimer's disease patients and in the blood of Parkinson's disease patients. Bacterial inflammagens, including lipopolysaccharides (LPSs) and various proteases in circulation, may drive systemic inflammation. Methods: Here, we investigate the effects of the bacterial products LPS from Escherichia coli and Porphyromonas gingivalis, and also the P. gingivalis gingipain [recombinant P. gingivalis gingipain R1 (RgpA)], on clot architecture and clot formation in whole blood and plasma from healthy individuals, as well as in purified fibrinogen models. Structural analysis of clots was performed using confocal microscopy, scanning electron microscopy, and AFM-Raman imaging. We use thromboelastography® (TEG®) and rheometry to compare the static and dynamic mechanical properties of clots. Results: We found that these inflammagens may interact with fibrin(ogen) and this interaction causes anomalous blood clotting. Conclusions: These techniques, in combination, provide insight into the effects of these bacterial products on cardiovascular health, and particularly clot structure and mechanics.
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Affiliation(s)
- J Massimo Nunes
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Tristan Fillis
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Martin J Page
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Chantelle Venter
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Ophélie Lancry
- HORIBA Scientific, HORIBA FRANCE SAS, Villeneuve-d'Ascq, France
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa.,Department of Biochemistry, Faculty of Health and Life Sciences, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Ursula Windberger
- Decentralised Biomedical Facilities, Centre for Biomedical Research, Medical University Vienna, Vienna, Austria
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
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23
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Grobler C, Maphumulo SC, Grobbelaar LM, Bredenkamp JC, Laubscher GJ, Lourens PJ, Steenkamp J, Kell DB, Pretorius E. Covid-19: The Rollercoaster of Fibrin(Ogen), D-Dimer, Von Willebrand Factor, P-Selectin and Their Interactions with Endothelial Cells, Platelets and Erythrocytes. Int J Mol Sci 2020; 21:ijms21145168. [PMID: 32708334 PMCID: PMC7403995 DOI: 10.3390/ijms21145168] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 02/07/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), also known as coronavirus disease 2019 (COVID-19)-induced infection, is strongly associated with various coagulopathies that may result in either bleeding and thrombocytopenia or hypercoagulation and thrombosis. Thrombotic and bleeding or thrombotic pathologies are significant accompaniments to acute respiratory syndrome and lung complications in COVID-19. Thrombotic events and bleeding often occur in subjects with weak constitutions, multiple risk factors and comorbidities. Of particular interest are the various circulating inflammatory coagulation biomarkers involved directly in clotting, with specific focus on fibrin(ogen), D-dimer, P-selectin and von Willebrand Factor (VWF). Central to the activity of these biomarkers are their receptors and signalling pathways on endothelial cells, platelets and erythrocytes. In this review, we discuss vascular implications of COVID-19 and relate this to circulating biomarker, endothelial, erythrocyte and platelet dysfunction. During the progression of the disease, these markers may either be within healthy levels, upregulated or eventually depleted. Most significant is that patients need to be treated early in the disease progression, when high levels of VWF, P-selectin and fibrinogen are present, with normal or slightly increased levels of D-dimer (however, D-dimer levels will rapidly increase as the disease progresses). Progression to VWF and fibrinogen depletion with high D-dimer levels and even higher P-selectin levels, followed by the cytokine storm, will be indicative of a poor prognosis. We conclude by looking at point-of-care devices and methodologies in COVID-19 management and suggest that a personalized medicine approach should be considered in the treatment of patients.
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Affiliation(s)
- Corlia Grobler
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch 7602, South Africa; (C.G.); (S.C.M.); (L.M.G.); (J.C.B.)
| | - Siphosethu C. Maphumulo
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch 7602, South Africa; (C.G.); (S.C.M.); (L.M.G.); (J.C.B.)
| | - L. Mireille Grobbelaar
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch 7602, South Africa; (C.G.); (S.C.M.); (L.M.G.); (J.C.B.)
| | - Jhade C. Bredenkamp
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch 7602, South Africa; (C.G.); (S.C.M.); (L.M.G.); (J.C.B.)
| | - Gert J. Laubscher
- Elsie du Toit Street, Stellenbosch MediClinic, Stellenbosch 7600, South Africa; (G.J.L.); (P.J.L.)
| | - Petrus J. Lourens
- Elsie du Toit Street, Stellenbosch MediClinic, Stellenbosch 7600, South Africa; (G.J.L.); (P.J.L.)
| | - Janami Steenkamp
- PathCare Laboratories, PathCare Business Centre, Neels Bothma Street, N1 City, Cape Town 7460, South Africa;
| | - Douglas B. Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch 7602, South Africa; (C.G.); (S.C.M.); (L.M.G.); (J.C.B.)
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- The Novo Nordisk Foundation Centre for Biosustainability, Building 220, Kemitorve Technical University of Denmark, 2800 Kongens Lyngby, Denmark
- Correspondence: (D.B.K.); (E.P.)
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch 7602, South Africa; (C.G.); (S.C.M.); (L.M.G.); (J.C.B.)
- Correspondence: (D.B.K.); (E.P.)
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24
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Alzheimer's disease-related dysregulation of mRNA translation causes key pathological features with ageing. Transl Psychiatry 2020; 10:192. [PMID: 32546772 PMCID: PMC7297996 DOI: 10.1038/s41398-020-00882-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 11/20/2022] Open
Abstract
Alzheimer's disease (AD) is characterised by Aβ and tau pathology as well as synaptic degeneration, which correlates best with cognitive impairment. Previous work suggested that this pathological complexity may result from changes in mRNA translation. Here, we studied whether mRNA translation and its underlying signalling are altered in an early model of AD, and whether modelling this deficiency in mice causes pathological features with ageing. Using an unbiased screen, we show that exposure of primary neurons to nanomolar amounts of Aβ increases FMRP-regulated protein synthesis. This selective regulation of mRNA translation is dependent on a signalling cascade involving MAPK-interacting kinase 1 (Mnk1) and the eukaryotic initiation factor 4E (eIF4E), and ultimately results in reduction of CYFIP2, an FMRP-binding protein. Modelling this CYFIP2 reduction in mice, we find age-dependent Aβ accumulation in the thalamus, development of tau pathology in entorhinal cortex and hippocampus, as well as gliosis and synapse loss in the hippocampus, together with deficits in memory formation. Therefore, we conclude that early stages of AD involve increased translation of specific CYFIP2/FMRP-regulated transcripts. Since reducing endogenous CYFIP2 expression is sufficient to cause key features of AD with ageing in mice, we suggest that prolonged activation of this pathway is a primary step toward AD pathology, highlighting a novel direction for therapeutic targeting.
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25
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Visser MJ, Pretorius E. Atomic Force Microscopy: The Characterisation of Amyloid Protein Structure in Pathology. Curr Top Med Chem 2020; 19:2958-2973. [DOI: 10.2174/1568026619666191121143240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/24/2019] [Accepted: 09/27/2019] [Indexed: 12/28/2022]
Abstract
:
Proteins are versatile macromolecules that perform a variety of functions and participate in
virtually all cellular processes. The functionality of a protein greatly depends on its structure and alterations
may result in the development of diseases. Most well-known of these are protein misfolding disorders,
which include Alzheimer’s and Parkinson’s diseases as well as type 2 diabetes mellitus, where
soluble proteins transition into insoluble amyloid fibrils. Atomic Force Microscopy (AFM) is capable of
providing a topographical map of the protein and/or its aggregates, as well as probing the nanomechanical
properties of a sample. Moreover, AFM requires relatively simple sample preparation, which presents
the possibility of combining this technique with other research modalities, such as confocal laser
scanning microscopy, Raman spectroscopy and stimulated emission depletion microscopy. In this review,
the basic principles of AFM are discussed, followed by a brief overview of how it has been applied
in biological research. Finally, we focus specifically on its use as a characterisation method to
study protein structure at the nanoscale in pathophysiological conditions, considering both molecules
implicated in disease pathogenesis and the plasma protein fibrinogen. In conclusion, AFM is a userfriendly
tool that supplies multi-parametric data, rendering it a most valuable technique.
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Affiliation(s)
- Maria J.E. Visser
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
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Fernández-Rojas B, Vázquez-Cervantes GI, Pedraza-Chaverri J, Gutiérrez-Venegas G. Lipoteichoic acid reduces antioxidant enzymes in H9c2 cells. Toxicol Rep 2019; 7:101-108. [PMID: 31921600 PMCID: PMC6948251 DOI: 10.1016/j.toxrep.2019.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 12/17/2019] [Accepted: 12/29/2019] [Indexed: 12/30/2022] Open
Abstract
Lipoteichoic acid (LTA) reduced the levels of the antioxidant enzymes in H9c2 cells. LTA from Streptococcus sanguinis induced ROS production in H9c2 cells. Low antioxidant enzymes levels and ROS production could be related to infective endocarditis (IE). Antioxidants could protect against oxidative stress induced by LTA in IE.
Infective endocarditis (IE) is an illness where the heart is invaded by bacteria, like Streptococcal and Staphylococcal species that contain lipoteichoic acid (LTA) related to an essential role in this disease. This study is the first in evaluating antioxidant enzyme levels in embryonic cardiomyocyte cell line (H9c2) induced by LTA from Streptococcus sanguinis. LTA increased reactive oxygen species (ROS) and reduced the levels of the antioxidant enzymes glutathione peroxidase, superoxide dismutase (SOD)-1 and catalase (CAT) but did not affect glutathione content. At the highest LTA concentration (15 μg/ml), SOD-1 and CAT levels did not change, and this effect was related to the induction of mRNA levels of Nrf2 induced by LTA. These results suggest that low antioxidant enzyme levels and ROS production could be related to IE.
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Key Words
- AKT, protein kinase B
- Antioxidant enzymes
- CAT, catalase
- Carboxy-H2DCFDA, 6-carboxy-2´,7´ dichlorodihydrofluorescein diacetate
- DHE, dihydroethidium
- ERK, extracellular signal-regulated kinases
- FDA, fluorescein diacetate
- GPx-1, glutathione peroxidase-1
- GSH, glutathione
- H2O2, hydrogen peroxide
- IE, infective endocarditis
- Infective endocarditis
- JNK, c-jun N-terminal kinases
- LTA, lipoteichoic acid
- Lipoteichoic acid
- MAPK, mitogen-activated protein kinase
- MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
- NO, nitric oxide
- NOS, nitric oxide synthase
- Nrf2, nuclear factor (erythroid-derived 2)-like 2
- O2•¯, superoxide radical
- OH•, hydroxyl radical
- ONOO¯, peroxynitrite anion
- Oxidative stress
- RNS, reactive nitrogen species
- ROS production
- ROS, reactive oxygen species
- SOD-1, superoxide dismutase-1
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Affiliation(s)
- Berenice Fernández-Rojas
- Laboratorio de Bioquímica de la División de Estudios de Posgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, México
| | - Gustavo I. Vázquez-Cervantes
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, Circuito interior s/n, Ciudad Universitaria, 04510, Ciudad de México, México
| | - José Pedraza-Chaverri
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, Circuito interior s/n, Ciudad Universitaria, 04510, Ciudad de México, México
| | - Gloria Gutiérrez-Venegas
- Laboratorio de Bioquímica de la División de Estudios de Posgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, México
- Corresponding author.
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Silva AF, Sousa JS, Cunha PL, Lima-Filho JV, Alencar NM, Freitas CD, Oliveira CL, Ramos MV. Erythrocytes morphology and hemorheology in severe bacterial infection. Mem Inst Oswaldo Cruz 2019; 114:e190326. [PMID: 31859703 PMCID: PMC6917465 DOI: 10.1590/0074-02760190326] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/25/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Severe bacterial infections initiate inadequate inflammation that leads to
disseminated intravascular coagulation and death. OBJECTIVES To evaluate the influence of bacterial infection on blood viscosity and red
blood cells (RBCs) morphology, and the ability of Calotropis
procera proteins (CpLP) to prevent the patho-hemorheology in
infected animals. METHODS Rheology of blood, atomic force microscopy measurements on specific blood
elements and blood count were performed to examine changes in blood
viscosity, RBCs morphology, platelets activation, and RBCs indices. FINDINGS Infected mice hold their blood rheological behaviour as compared to that of
the control group. However, they presented hyperactivated platelets, RBCs at
different stages of eryptosis, and variation on RBCs indices. CpLP
administration in healthy animals altered blood behaviour from pseudoplastic
to Bingham-like fluid. Such effect disappeared over time and by inhibiting
its proteases. No alterations were observed in RBCs morphology or platelets.
Treatment of infected animals with CpLP prevented the changes in RBCs
indices and morphology. MAIN CONCLUSIONS The inflammatory process triggered by bacterial infection induced
pathological changes in RBCs and platelets activation. Treatment of infected
animals with CpLP prevented the emergence of RBCs abnormal morphology and
this may have implications in the protective effect of CpLP, avoiding animal
death.
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Affiliation(s)
- Ayrles Fb Silva
- Universidade Federal do Ceará, Departamento de Bioquímica e Biologia Molecular, Fortaleza, CE, Brasil
| | - Jeanlex S Sousa
- Universidade Federal do Ceará, Departamento de Física, Fortaleza, CE, Brasil
| | - Pablyana Lr Cunha
- Universidade Federal do Ceará, Departamento de Química Orgânica e Inorgânica, Fortaleza, CE, Brasil
| | - José V Lima-Filho
- Universidade Federal Rural de Pernambuco, Departamento de Biologia, Recife, PE, Brasil
| | - Nylane Mn Alencar
- Universidade Federal do Ceará, Departamento de Fisiologia e Farmacologia, Fortaleza, CE, Brasil
| | - Cleverson Dt Freitas
- Universidade Federal do Ceará, Departamento de Bioquímica e Biologia Molecular, Fortaleza, CE, Brasil
| | - Claudio Ln Oliveira
- Universidade Federal do Ceará, Departamento de Física, Fortaleza, CE, Brasil
| | - Marcio V Ramos
- Universidade Federal do Ceará, Departamento de Bioquímica e Biologia Molecular, Fortaleza, CE, Brasil
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Farkas ÁZ, Farkas VJ, Szabó L, Wacha A, Bóta A, Csehi L, Kolev K, Thelwell C. Structure, Mechanical, and Lytic Stability of Fibrin and Plasma Coagulum Generated by Staphylocoagulase From Staphylococcus aureus. Front Immunol 2019; 10:2967. [PMID: 31921206 PMCID: PMC6933771 DOI: 10.3389/fimmu.2019.02967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 12/03/2019] [Indexed: 12/18/2022] Open
Abstract
Staphylococcus aureus causes localized infections or invasive diseases (abscesses or endocarditis). One of its virulence factors is staphylocoagulase (SCG), which binds prothrombin to form a complex with thrombin-like proteolytic activity and leads to uncontrolled fibrin generation at sites of bacterial inoculation. The aim of this study was to characterize the formation, structure, mechanical properties and lysis of SCG-generated clots. Recombinant SCG was expressed in Escherichia coli, purified and the amidolytic activity of its complexes with human prothrombin (SCG-PT) and thrombin (SCG-T) was determined using human thrombin as a reference. Fibrin clots were prepared from purified fibrinogen and human plasma using thrombin, SCG-PT or SCG-T as a coagulase. The kinetics of clot formation and lysis by tissue-type plasminogen activator (tPA) were monitored with turbidimetric assays. Fibrin ultrastructure was examined with scanning electron microscopy and small-angle X-ray scattering (SAXS). Fibrin clot porosity was characterized with fluid permeation assays, whereas the viscoelastic properties and mechanical stability were evaluated with oscillation rheometry. Compared to thrombin, the amidolytic and clotting activity of SCG-PT was 1.6- to 2.5-fold lower on a molar basis. SCG-T had equivalent amidolytic, but reduced clotting activity both on pure fibrinogen (1.6-fold), and in plasma (1.3-fold). The SCG-PT and SCG-T generated fibrin with thicker fibers (10-60% increase in median diameter) than thrombin due to increased number of fibrin protofibrils per fiber cross-section. According to the fluid permeability of the clots SCG-PT and SCG-T promoted the formation of more porous structures. The shear stress resistance in the pure fibrin and plasma clots generated by SCG-PT was significantly lower than in the thrombin clots (243.8 ± 22.0 Pa shear stress was sufficient for disassembly of SCG-PT fibrin vs. 937.3 ± 65.6 Pa in thrombin clots). The tPA-mediated lysis of both pure fibrin and plasma clots produced by SCG-PT or SCG-T was accelerated compared to thrombin, resulting in up to a 2.1-fold increase in tPA potency. Our results indicate that SCG generates a thrombus scaffold with a structure characterized by impaired mechanical stability and increased lytic susceptibility. This proneness to clot disintegration could have implications in the septic embolism from endocardial bacterial vegetation.
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Affiliation(s)
- Ádám Z Farkas
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Veronika J Farkas
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - László Szabó
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - András Wacha
- Biological Nanochemistry Research Group, Research Centre for Natural Sciences, Budapest, Hungary
| | - Attila Bóta
- Biological Nanochemistry Research Group, Research Centre for Natural Sciences, Budapest, Hungary
| | - Lóránt Csehi
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Krasimir Kolev
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Craig Thelwell
- Haemostasis Section, Biotherapeutics Group, National Institute for Standards and Control, Potters Bar, United Kingdom
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Adams B, Nunes JM, Page MJ, Roberts T, Carr J, Nell TA, Kell DB, Pretorius E. Parkinson's Disease: A Systemic Inflammatory Disease Accompanied by Bacterial Inflammagens. Front Aging Neurosci 2019; 11:210. [PMID: 31507404 PMCID: PMC6718721 DOI: 10.3389/fnagi.2019.00210] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/26/2019] [Indexed: 01/08/2023] Open
Abstract
Parkinson’s disease (PD) is a well-known neurodegenerative disease with a strong association established with systemic inflammation. Recently, the role of the gingipain protease group from Porphyromonas gingivalis was implicated in Alzheimer’s disease and here we present evidence, using a fluorescent antibody to detect gingipain R1 (RgpA), of its presence in a PD population. To further elucidate the action of this gingipain, as well as the action of the lipopolysaccharide (LPS) from P. gingivalis, low concentrations of recombinant RgpA and LPS were added to purified fluorescent fibrinogen. We also substantiate previous findings regarding PD by emphasizing the presence of systemic inflammation via multiplex cytokine analysis, and demonstrate hypercoagulation using thromboelastography (TEG), confocal and electron microscopy. Biomarker analysis confirmed significantly increased levels of circulating proinflammatory cytokines. In our PD and control blood analysis, our results show increased hypercoagulation, the presence of amyloid formation in plasma, and profound ultrastructural changes to platelets. Our laboratory analysis of purified fibrinogen with added RgpA, and/or LPS, showed preliminary data with regards to the actions of the protease and the bacterial membrane inflammagen on plasma proteins, to better understand the nature of established PD.
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Affiliation(s)
- Büin Adams
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - J Massimo Nunes
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Martin J Page
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Timothy Roberts
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa.,Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Jonathan Carr
- Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Theo A Nell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa.,Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
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Page MJ, Thomson GJA, Nunes JM, Engelbrecht AM, Nell TA, de Villiers WJS, de Beer MC, Engelbrecht L, Kell DB, Pretorius E. Serum amyloid A binds to fibrin(ogen), promoting fibrin amyloid formation. Sci Rep 2019; 9:3102. [PMID: 30816210 PMCID: PMC6395759 DOI: 10.1038/s41598-019-39056-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 01/16/2019] [Indexed: 12/15/2022] Open
Abstract
Complex associations exist between inflammation and thrombosis, with the inflammatory state tending to promote coagulation. Fibrinogen, an acute phase protein, has been shown to interact with the amyloidogenic ß-amyloid protein of Alzheimer’s disease. However, little is known about the association between fibrinogen and serum amyloid A (SAA), a highly fibrillogenic protein that is one of the most dramatically changing acute phase reactants in the circulation. To study the role of SAA in coagulation and thrombosis, in vitro experiments were performed where purified human SAA, in concentrations resembling a modest acute phase response, was added to platelet-poor plasma (PPP) and whole blood (WB), as well as purified and fluorescently labelled fibrinogen. Results from thromboelastography (TEG) suggest that SAA causes atypical coagulation with a fibrin(ogen)-mediated increase in coagulation, but a decreased platelet/fibrin(ogen) interaction. In WB scanning electron microscopy analysis, SAA mediated red blood cell (RBC) agglutination, platelet activation and clumping, but not platelet spreading. Following clot formation in PPP, the presence of SAA increased amyloid formation of fibrin(ogen) as determined both with auto-fluorescence and with fluorogenic amyloid markers, under confocal microcopy. SAA also binds to fibrinogen, as determined with a fluorescent-labelled SAA antibody and correlative light electron microscopy (CLEM). The data presented here indicate that SAA can affect coagulation by inducing amyloid formation in fibrin(ogen), as well as by propelling platelets to a more prothrombotic state. The discovery of these multiple and complex effects of SAA on coagulation invite further mechanistic analyses.
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Affiliation(s)
- Martin J Page
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa
| | - Greig J A Thomson
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa
| | - J Massimo Nunes
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa
| | - Anna-Mart Engelbrecht
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa
| | - Theo A Nell
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa
| | - Willem J S de Villiers
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa.,Department of Internal Medicine, Stellenbosch University, Stellenbosch, South Africa
| | - Maria C de Beer
- Department of Physiology, Saha Cardiovascular Research Center and Barnstable Brown Diabetes Center, University of Kentucky, Lexington, KY, USA
| | - Lize Engelbrecht
- Fluorescence Microscopy Unit, Central Analytical Facilities, Stellenbosch University, Stellenbosch, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa. .,School of Chemistry, The University of Manchester, 131 Princess St, MANCHESTER M1 7DN, Lancs, UK. .,The Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, MANCHESTER M1 7DN, Lancs, UK. .,Department of Biochemistry, Institute of integrative Biology, Biosciences Building., University of Liverpool, Crown St, Liverpool, L69 7ZB, UK.
| | - Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, Stellenbosch, South Africa.
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31
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Pretorius L, Kell DB, Pretorius E. Iron Dysregulation and Dormant Microbes as Causative Agents for Impaired Blood Rheology and Pathological Clotting in Alzheimer's Type Dementia. Front Neurosci 2018; 12:851. [PMID: 30519157 PMCID: PMC6251002 DOI: 10.3389/fnins.2018.00851] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 10/30/2018] [Indexed: 12/13/2022] Open
Abstract
Alzheimer’s disease and other similar dementias are debilitating neurodegenerative disorders whose etiology and pathogenesis remain largely unknown, even after decades of research. With the anticipated increase in prevalence of Alzheimer’s type dementias among the more susceptible aging population, the need for disease-modifying treatments is urgent. While various hypotheses have been put forward over the last few decades, we suggest that Alzheimer’s type dementias are triggered by external environmental factors, co-expressing in individuals with specific genetic susceptibilities. These external stressors are defined in the Iron Dysregulation and Dormant Microbes (IDDM) hypothesis, previously put forward. This hypothesis is consistent with current literature in which serum ferritin levels of individuals diagnosed with Alzheimer’s disease are significantly higher compared those of age- and gender-matched controls. While iron dysregulation contributes to oxidative stress, it also causes microbial reactivation and virulence of the so-called dormant blood (and tissue) microbiome. Dysbiosis (changes in the microbiome) or previous infections can contribute to the dormant blood microbiome (atopobiosis1), and also directly promotes systemic inflammation via the amyloidogenic formation and shedding of potent inflammagens such as lipopolysaccharides. The simultaneous iron dysregulation and microbial aberrations affect the hematological system, promoting fibrin amylodiogenesis, and pathological clotting. Systemic inflammation and oxidative stress can contribute to blood brain barrier permeability and the ensuing neuro-inflammation, characteristic of Alzheimer’s type dementias. While large inter-individual variability exists, especially concerning disease pathogenesis, the IDDM hypothesis acknowledges primary causative factors which can be targeted for early diagnosis and/or for prevention of disease progression.
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Affiliation(s)
- Lesha Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Douglas B Kell
- School of Chemistry, The University of Manchester, Manchester, United Kingdom.,The Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
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de Waal GM, Engelbrecht L, Davis T, de Villiers WJS, Kell DB, Pretorius E. Correlative Light-Electron Microscopy detects lipopolysaccharide and its association with fibrin fibres in Parkinson's Disease, Alzheimer's Disease and Type 2 Diabetes Mellitus. Sci Rep 2018; 8:16798. [PMID: 30429533 PMCID: PMC6235901 DOI: 10.1038/s41598-018-35009-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/27/2018] [Indexed: 02/06/2023] Open
Abstract
Many chronic diseases, including those classified as cardiovascular, neurodegenerative, or autoimmune, are characterized by persistent inflammation. The origin of this inflammation is mostly unclear, but it is typically mediated by inflammatory biomarkers, such as cytokines, and affected by both environmental and genetic factors. Recently circulating bacterial inflammagens such as lipopolysaccharide (LPS) have been implicated. We used a highly selective mouse monoclonal antibody to detect bacterial LPS in whole blood and/or platelet poor plasma of individuals with Parkinson’s Disease, Alzheimer’s type dementia, or Type 2 Diabetes Mellitus. Our results showed that staining is significantly enhanced (P < 0.0001) compared to healthy controls. Aberrant blood clots in these patient groups are characterized by amyloid formation as shown by the amyloid-selective stains thioflavin T and Amytracker™ 480 or 680. Correlative Light-Electron Microscopy (CLEM) illustrated that the LPS antibody staining is located in the same places as where amyloid fibrils may be observed. These data are consistent with the Iron Dysregulation and Dormant Microbes (IDDM) hypothesis in which bacterial inflammagens such as LPS are responsible for anomalous blood clotting as part of the aetiology of these chronic inflammatory diseases.
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Affiliation(s)
- Greta M de Waal
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Lize Engelbrecht
- Central Analytical Facilities, Fluorescence Microscopy Unit, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Tanja Davis
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Willem J S de Villiers
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa.,Department of Internal Medicine, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa.,School of Chemistry, The University of Manchester, 131 Princess St, Manchester, Lancs, M1 7DN, UK.,Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, Lancs, M1 7DN, UK
| | - Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa.
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33
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Pretorius L, Thomson GJA, Adams RCM, Nell TA, Laubscher WA, Pretorius E. Platelet activity and hypercoagulation in type 2 diabetes. Cardiovasc Diabetol 2018; 17:141. [PMID: 30388964 PMCID: PMC6214175 DOI: 10.1186/s12933-018-0783-z] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/26/2018] [Indexed: 02/07/2023] Open
Abstract
Background A strong correlation exists between type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), with CVD and the presence of atherosclerosis being the prevailing cause of morbidity and mortality in diabetic populations. T2DM is accompanied by various coagulopathies, including anomalous clot formation or amyloid fibrin(ogen), the presence of dysregulated inflammatory molecules. Platelets are intimately involved in thrombus formation and particularly vulnerable to inflammatory cytokines. Methods The aim of this current study was therefore to assess whole blood (hyper)coagulability, platelet ultrastructure and receptor expression, as well as the levels of IL-1β, IL-6, IL-8 and sP-selectin in healthy and diabetic individuals. Platelet morphology was assessed through scanning electron microscopy (SEM), while assessment of GPIIb/IIIa receptor expression was performed with confocal microscopy and flow cytometry with the addition of FITC-PAC-1 and CD41-PE antibodies. IL-1β, IL-6 and IL-8 and sP-selectin levels were assessed using a multiplex assay. Results In T2DM there is significant upregulation of circulating inflammatory markers, hypercoagulation and platelet activation, with increased GPIIb/IIIa receptor expression, as seen with flow cytometry and confocal microscopy. Analyses showed that these receptors were additionally shed onto microparticles, which was confirmed with SEM. Conclusions Cumulatively, this provides mechanistic evidence that pathological states of platelets together with amyloid fibrin(ogen) in T2DM, might underpin an increased risk for cardiovascular events.
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Affiliation(s)
- Lesha Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa
| | - Greig J A Thomson
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa
| | - Rozanne C M Adams
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa.,Central Analytical Facilities, Fluorescence Imaging Unit Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa
| | - Theo A Nell
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa
| | - Willem A Laubscher
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa.,Department of Electronic and Electric Engineering, Faculty of Engineering, Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa
| | - Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1, Stellenbosch, 7602, South Africa.
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Pretorius E, Bester J, Page MJ, Kell DB. The Potential of LPS-Binding Protein to Reverse Amyloid Formation in Plasma Fibrin of Individuals With Alzheimer-Type Dementia. Front Aging Neurosci 2018; 10:257. [PMID: 30186156 PMCID: PMC6113936 DOI: 10.3389/fnagi.2018.00257] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 08/03/2018] [Indexed: 12/28/2022] Open
Abstract
Many studies indicate that there is a (mainly dormant) microbial component in the progressive development of Alzheimer-type dementias (ADs); and that in the case of Gram-negative organisms, a chief culprit might be the shedding of the highly inflammagenic lipopolysaccharide (LPS) from their cell walls. We have recently shown that a highly sensitive assay for the presence of free LPS [added to platelet poor plasma (PPP)] lies in its ability (in healthy individuals) to induce blood to clot into an amyloid form. This may be observed in a SEM or in a confocal microscope when suitable amyloid stains (such as thioflavin T) are added. This process could be inhibited by human lipopolysaccharide-binding protein (LBP). In the current paper, we show using scanning electron microscopy and confocal microscopy with amyloid markers, that PPP taken from individuals with AD exhibits considerable amyloid structure when clotting is initiated with thrombin but without added LPS. Furthermore, we could show that this amyloid structure may be reversed by the addition of very small amounts of LBP. This provides further evidence for a role of microbes and their inflammagenic cell wall products and that these products may be involved in pathological clotting in individuals with AD.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Martin J Page
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa.,School of Chemistry, The University of Manchester, Manchester, United Kingdom.,The Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
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Kell DB, Pretorius E. No effects without causes: the Iron Dysregulation and Dormant Microbes hypothesis for chronic, inflammatory diseases. Biol Rev Camb Philos Soc 2018; 93:1518-1557. [PMID: 29575574 PMCID: PMC6055827 DOI: 10.1111/brv.12407] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/12/2018] [Accepted: 02/15/2018] [Indexed: 12/11/2022]
Abstract
Since the successful conquest of many acute, communicable (infectious) diseases through the use of vaccines and antibiotics, the currently most prevalent diseases are chronic and progressive in nature, and are all accompanied by inflammation. These diseases include neurodegenerative (e.g. Alzheimer's, Parkinson's), vascular (e.g. atherosclerosis, pre-eclampsia, type 2 diabetes) and autoimmune (e.g. rheumatoid arthritis and multiple sclerosis) diseases that may appear to have little in common. In fact they all share significant features, in particular chronic inflammation and its attendant inflammatory cytokines. Such effects do not happen without underlying and initially 'external' causes, and it is of interest to seek these causes. Taking a systems approach, we argue that these causes include (i) stress-induced iron dysregulation, and (ii) its ability to awaken dormant, non-replicating microbes with which the host has become infected. Other external causes may be dietary. Such microbes are capable of shedding small, but functionally significant amounts of highly inflammagenic molecules such as lipopolysaccharide and lipoteichoic acid. Sequelae include significant coagulopathies, not least the recently discovered amyloidogenic clotting of blood, leading to cell death and the release of further inflammagens. The extensive evidence discussed here implies, as was found with ulcers, that almost all chronic, infectious diseases do in fact harbour a microbial component. What differs is simply the microbes and the anatomical location from and at which they exert damage. This analysis offers novel avenues for diagnosis and treatment.
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Affiliation(s)
- Douglas B. Kell
- School of ChemistryThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- The Manchester Institute of BiotechnologyThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
| | - Etheresia Pretorius
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
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Zhao Y, Lukiw WJ. Bacteroidetes Neurotoxins and Inflammatory Neurodegeneration. Mol Neurobiol 2018; 55:9100-9107. [PMID: 29637444 DOI: 10.1007/s12035-018-1015-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/16/2018] [Indexed: 12/31/2022]
Abstract
The gram-negative facultative anaerobe Bacteroides fragilis (B. fragilis) constitutes an appreciable proportion of the human gastrointestinal (GI)-tract microbiome. As is typical of most gram-negative bacilli, B. fragilis secretes an unusually complex mixture of neurotoxins including the extremely pro-inflammatory lipopolysaccharide BF-LPS. LPS (i) has recently been shown to associate with the periphery of neuronal nuclei in sporadic Alzheimer's disease (AD) brain and (ii) promotes the generation of the inflammatory transcription factor NF-kB (p50/p65 complex) in human neuronal-glial cells in primary-culture. In turn, the NF-kB (p50/p65 complex) strongly induces the transcription of a small family of pro-inflammatory microRNAs (miRNAs) including miRNA-9, miRNA-34a, miRNA-125b, miRNA-146a, and miRNA-155. These ultimately bind with the 3'-untranslated region (3'-UTR) of several target messenger RNAs (mRNAs) and thereby reduce their expression. Down-regulated mRNAs include those encoding complement factor-H (CFH), an SH3-proline-rich multi-domain-scaffolding protein of the postsynaptic density (SHANK3), and the triggering receptor expressed in myeloid/microglial cells (TREM2), as is observed in sporadic AD brain. Hence, a LPS normally confined to the GI tract is capable of driving a NF-kB-miRNA-mediated deficiency in gene expression that contributes to alterations in synaptic-architecture and synaptic-deficits, amyloidogenesis, innate-immune defects, and progressive inflammatory signaling, all of which are characteristics of AD-type neurodegeneration. This article will review the most recent research which supports the idea that bacterial components of the GI tract microbiome such as BF-LPS can transverse biophysical barriers and contribute to AD-type change. For the first-time, these results indicate that specific GI tract microbiome-derived neurotoxins have a strong pathogenic role in eliciting alterations in NF-kB-miRNA-directed gene expression that drives the AD process.
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Affiliation(s)
- Yuhai Zhao
- LSU Neuroscience Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans, LA, 70112, USA.,Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans, LA, 70112, USA
| | - Walter J Lukiw
- LSU Neuroscience Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans, LA, 70112, USA. .,Department of Neurology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans, LA, 70112, USA. .,Departments of Ophthalmology, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite 904, New Orleans, LA, 70112, USA.
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Pretorius E, Page MJ, Engelbrecht L, Ellis GC, Kell DB. Substantial fibrin amyloidogenesis in type 2 diabetes assessed using amyloid-selective fluorescent stains. Cardiovasc Diabetol 2017; 16:141. [PMID: 29096623 PMCID: PMC5668975 DOI: 10.1186/s12933-017-0624-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 10/23/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND We have previously shown that many chronic, inflammatory diseases are accompanied, and possibly partly caused or exacerbated, by various coagulopathies, manifested as anomalous clots in the form of 'dense matted deposits'. More recently, we have shown that these clots can be amyloid in nature, and that the plasma of healthy controls can be induced to form such clots by the addition of tiny amounts of bacterial lipopolysaccharide or lipoteichoic acid. Type 2 diabetes (T2D) is also accompanied by raised levels of LPS. METHODS We use superresolution and confocal microscopies to investigate the amyloid nature of clots from healthy and T2D individuals. RESULTS We show here, with the established stain thioflavin T and the novel stains Amytracker™ 480 and 680, that the clotting of plasma from type 2 diabetics is also amyloid in nature, and that this may be prevented by the addition of suitable concentrations of LPS-binding protein. CONCLUSION This implies strongly that there is indeed a microbial component to the development of type 2 diabetes, and suggests that LBP might be used as treatment for it and its sequelae.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa.
| | - Martin J Page
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa
| | - Lize Engelbrecht
- Central Analytical Facility, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa
| | - Graham C Ellis
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa.,Synexus Helderberg Clinical Research Centre, Helderberg Synexus South Africa, 7G&H Arun Place, Somerset West, 7130, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa. .,School of Chemistry and Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, Lancs, UK.
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